zynaddsubfx

commit d5fddf5b9598c743c271424adf93b1284e6f8543
parent 33f16b1d6550a28b023605ee7ff534a1d6909e28
Author: Ricard Wanderlof <polluxsynth@butoba.net>
Date:   Tue, 15 Mar 2022 00:10:56 +0100

AnalogFilter: Always grab latest Q when recalculating coeffs (#347)

Even though a Q change only forces a recompute if the Q has
changed by more than 10%, if for whatever reason (like a frequency
change) we need to recalculate the filter coeffs, grab the latest
set Q value, regardless if it is more than 10% from the previous
value or not.

Diffstat:
M
src/DSP/AnalogFilter.cpp
 | 
10
++++++----
M
src/DSP/AnalogFilter.h
 | 
1
+

2 files changed, 7 insertions(+), 4 deletions(-)
diff --git a/src/DSP/AnalogFilter.cpp b/src/DSP/AnalogFilter.cpp
@@ -35,6 +35,7 @@ AnalogFilter::AnalogFilter(unsigned char Ftype,
       stages(Fstages),
       freq(Ffreq),
       q(Fq),
+      newq(Fq),
      gain(1.0),
      recompute(true),
      freqbufsize(bufsize/8)
@@ -292,6 +293,8 @@ void AnalogFilter::setfreq(float frequency)
         freq = frequency;
         recompute = true;
     }
+    if (recompute)
+        q = newq;
     
     if (beforeFirstTick) {
         freq_smoothing.reset( freq );
@@ -301,22 +304,21 @@ void AnalogFilter::setfreq(float frequency)
 
 void AnalogFilter::setfreq_and_q(float frequency, float q_)
 {
+    newq = q_;
     /*
      * Only recompute based on Q change if change is more than 10%
      * from current value (or the old or new Q is 0, which normally
      * won't occur, but better to handle it than potentially
      * fail on division by zero or assert).
      */
-    if (q == 0.0 || q_ == 0.0 || ((q > q_ ? q / q_ : q_ / q) > 1.1)) {
-        q = q_;
+    if (q == 0.0 || q_ == 0.0 || ((q > q_ ? q / q_ : q_ / q) > 1.1))
         recompute = true;
-    }
     setfreq(frequency);
 }
 
 void AnalogFilter::setq(float q_)
 {
-    q = q_;
+    newq = q = q_;
     computefiltercoefs(freq,q);
 }
 
diff --git a/src/DSP/AnalogFilter.h b/src/DSP/AnalogFilter.h
@@ -69,6 +69,7 @@ class AnalogFilter:public Filter
         int   stages; //how many times the filter is applied (0->1,1->2,etc.)
         float freq;   //Frequency given in Hz
         float q;      //Q factor (resonance or Q factor)
+        float newq;   //New target Q
         float gain;   //the gain of the filter (if are shelf/peak) filters
         bool recompute; // need to recompute coeff.
         int order; //the order of the filter (number of poles)